xref: /openbmc/linux/scripts/kconfig/lexer.l (revision fb574682)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
4  */
5 %option nostdinit noyywrap never-interactive full ecs
6 %option 8bit nodefault yylineno
7 %x ASSIGN_VAL HELP STRING
8 %{
9 
10 #include <assert.h>
11 #include <limits.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <unistd.h>
16 
17 #include "lkc.h"
18 #include "parser.tab.h"
19 
20 #define YY_DECL		static int yylex1(void)
21 
22 #define START_STRSIZE	16
23 
24 static struct {
25 	struct file *file;
26 	int lineno;
27 } current_pos;
28 
29 static int prev_prev_token = T_EOL;
30 static int prev_token = T_EOL;
31 static char *text;
32 static int text_size, text_asize;
33 
34 struct buffer {
35 	struct buffer *parent;
36 	YY_BUFFER_STATE state;
37 };
38 
39 struct buffer *current_buf;
40 
41 static int last_ts, first_ts;
42 
43 static char *expand_token(const char *in, size_t n);
44 static void append_expanded_string(const char *in);
45 static void zconf_endhelp(void);
46 static void zconf_endfile(void);
47 
48 static void new_string(void)
49 {
50 	text = xmalloc(START_STRSIZE);
51 	text_asize = START_STRSIZE;
52 	text_size = 0;
53 	*text = 0;
54 }
55 
56 static void append_string(const char *str, int size)
57 {
58 	int new_size = text_size + size + 1;
59 	if (new_size > text_asize) {
60 		new_size += START_STRSIZE - 1;
61 		new_size &= -START_STRSIZE;
62 		text = xrealloc(text, new_size);
63 		text_asize = new_size;
64 	}
65 	memcpy(text + text_size, str, size);
66 	text_size += size;
67 	text[text_size] = 0;
68 }
69 
70 static void alloc_string(const char *str, int size)
71 {
72 	text = xmalloc(size + 1);
73 	memcpy(text, str, size);
74 	text[size] = 0;
75 }
76 
77 static void warn_ignored_character(char chr)
78 {
79 	fprintf(stderr,
80 	        "%s:%d:warning: ignoring unsupported character '%c'\n",
81 	        current_file->name, yylineno, chr);
82 }
83 %}
84 
85 n	[A-Za-z0-9_-]
86 
87 %%
88 	int str = 0;
89 	int ts, i;
90 
91 #.*			/* ignore comment */
92 [ \t]*			/* whitespaces */
93 \\\n			/* escaped new line */
94 \n			return T_EOL;
95 "allnoconfig_y"		return T_ALLNOCONFIG_Y;
96 "bool"			return T_BOOL;
97 "choice"		return T_CHOICE;
98 "comment"		return T_COMMENT;
99 "config"		return T_CONFIG;
100 "def_bool"		return T_DEF_BOOL;
101 "def_tristate"		return T_DEF_TRISTATE;
102 "default"		return T_DEFAULT;
103 "defconfig_list"	return T_DEFCONFIG_LIST;
104 "depends"		return T_DEPENDS;
105 "endchoice"		return T_ENDCHOICE;
106 "endif"			return T_ENDIF;
107 "endmenu"		return T_ENDMENU;
108 "help"|"---help---"	return T_HELP;
109 "hex"			return T_HEX;
110 "if"			return T_IF;
111 "imply"			return T_IMPLY;
112 "int"			return T_INT;
113 "mainmenu"		return T_MAINMENU;
114 "menu"			return T_MENU;
115 "menuconfig"		return T_MENUCONFIG;
116 "modules"		return T_MODULES;
117 "on"			return T_ON;
118 "option"		return T_OPTION;
119 "optional"		return T_OPTIONAL;
120 "prompt"		return T_PROMPT;
121 "range"			return T_RANGE;
122 "select"		return T_SELECT;
123 "source"		return T_SOURCE;
124 "string"		return T_STRING;
125 "tristate"		return T_TRISTATE;
126 "visible"		return T_VISIBLE;
127 "||"			return T_OR;
128 "&&"			return T_AND;
129 "="			return T_EQUAL;
130 "!="			return T_UNEQUAL;
131 "<"			return T_LESS;
132 "<="			return T_LESS_EQUAL;
133 ">"			return T_GREATER;
134 ">="			return T_GREATER_EQUAL;
135 "!"			return T_NOT;
136 "("			return T_OPEN_PAREN;
137 ")"			return T_CLOSE_PAREN;
138 ":="			return T_COLON_EQUAL;
139 "+="			return T_PLUS_EQUAL;
140 \"|\'			{
141 				str = yytext[0];
142 				new_string();
143 				BEGIN(STRING);
144 			}
145 {n}+			{
146 				alloc_string(yytext, yyleng);
147 				yylval.string = text;
148 				return T_WORD;
149 			}
150 ({n}|$)+		{
151 				/* this token includes at least one '$' */
152 				yylval.string = expand_token(yytext, yyleng);
153 				if (strlen(yylval.string))
154 					return T_WORD;
155 				free(yylval.string);
156 			}
157 .			warn_ignored_character(*yytext);
158 
159 <ASSIGN_VAL>{
160 	[^[:blank:]\n]+.*	{
161 		alloc_string(yytext, yyleng);
162 		yylval.string = text;
163 		return T_ASSIGN_VAL;
164 	}
165 	\n	{ BEGIN(INITIAL); return T_EOL; }
166 	.
167 }
168 
169 <STRING>{
170 	"$".*	append_expanded_string(yytext);
171 	[^$'"\\\n]+	{
172 		append_string(yytext, yyleng);
173 	}
174 	\\.?	{
175 		append_string(yytext + 1, yyleng - 1);
176 	}
177 	\'|\"	{
178 		if (str == yytext[0]) {
179 			BEGIN(INITIAL);
180 			yylval.string = text;
181 			return T_WORD_QUOTE;
182 		} else
183 			append_string(yytext, 1);
184 	}
185 	\n	{
186 		fprintf(stderr,
187 			"%s:%d:warning: multi-line strings not supported\n",
188 			zconf_curname(), zconf_lineno());
189 		unput('\n');
190 		BEGIN(INITIAL);
191 		yylval.string = text;
192 		return T_WORD_QUOTE;
193 	}
194 	<<EOF>>	{
195 		BEGIN(INITIAL);
196 		yylval.string = text;
197 		return T_WORD_QUOTE;
198 	}
199 }
200 
201 <HELP>{
202 	[ \t]+	{
203 		ts = 0;
204 		for (i = 0; i < yyleng; i++) {
205 			if (yytext[i] == '\t')
206 				ts = (ts & ~7) + 8;
207 			else
208 				ts++;
209 		}
210 		last_ts = ts;
211 		if (first_ts) {
212 			if (ts < first_ts) {
213 				zconf_endhelp();
214 				return T_HELPTEXT;
215 			}
216 			ts -= first_ts;
217 			while (ts > 8) {
218 				append_string("        ", 8);
219 				ts -= 8;
220 			}
221 			append_string("        ", ts);
222 		}
223 	}
224 	[ \t]*\n/[^ \t\n] {
225 		zconf_endhelp();
226 		return T_HELPTEXT;
227 	}
228 	[ \t]*\n	{
229 		append_string("\n", 1);
230 	}
231 	[^ \t\n].* {
232 		while (yyleng) {
233 			if ((yytext[yyleng-1] != ' ') && (yytext[yyleng-1] != '\t'))
234 				break;
235 			yyleng--;
236 		}
237 		append_string(yytext, yyleng);
238 		if (!first_ts)
239 			first_ts = last_ts;
240 	}
241 	<<EOF>>	{
242 		zconf_endhelp();
243 		return T_HELPTEXT;
244 	}
245 }
246 
247 <<EOF>>	{
248 	BEGIN(INITIAL);
249 
250 	if (prev_token != T_EOL && prev_token != T_HELPTEXT)
251 		fprintf(stderr, "%s:%d:warning: no new line at end of file\n",
252 			current_file->name, yylineno);
253 
254 	if (current_file) {
255 		zconf_endfile();
256 		return T_EOL;
257 	}
258 	fclose(yyin);
259 	yyterminate();
260 }
261 
262 %%
263 
264 /* second stage lexer */
265 int yylex(void)
266 {
267 	int token;
268 
269 repeat:
270 	token = yylex1();
271 
272 	if (prev_token == T_EOL || prev_token == T_HELPTEXT) {
273 		if (token == T_EOL) {
274 			/* Do not pass unneeded T_EOL to the parser. */
275 			goto repeat;
276 		} else {
277 			/*
278 			 * For the parser, update file/lineno at the first token
279 			 * of each statement. Generally, \n is a statement
280 			 * terminator in Kconfig, but it is not always true
281 			 * because \n could be escaped by a backslash.
282 			 */
283 			current_pos.file = current_file;
284 			current_pos.lineno = yylineno;
285 		}
286 	}
287 
288 	if (prev_prev_token == T_EOL && prev_token == T_WORD &&
289 	    (token == T_EQUAL || token == T_COLON_EQUAL || token == T_PLUS_EQUAL))
290 		BEGIN(ASSIGN_VAL);
291 
292 	prev_prev_token = prev_token;
293 	prev_token = token;
294 
295 	return token;
296 }
297 
298 static char *expand_token(const char *in, size_t n)
299 {
300 	char *out;
301 	int c;
302 	char c2;
303 	const char *rest, *end;
304 
305 	new_string();
306 	append_string(in, n);
307 
308 	/* get the whole line because we do not know the end of token. */
309 	while ((c = input()) != EOF) {
310 		if (c == '\n') {
311 			unput(c);
312 			break;
313 		}
314 		c2 = c;
315 		append_string(&c2, 1);
316 	}
317 
318 	rest = text;
319 	out = expand_one_token(&rest);
320 
321 	/* push back unused characters to the input stream */
322 	end = rest + strlen(rest);
323 	while (end > rest)
324 		unput(*--end);
325 
326 	free(text);
327 
328 	return out;
329 }
330 
331 static void append_expanded_string(const char *str)
332 {
333 	const char *end;
334 	char *res;
335 
336 	str++;
337 
338 	res = expand_dollar(&str);
339 
340 	/* push back unused characters to the input stream */
341 	end = str + strlen(str);
342 	while (end > str)
343 		unput(*--end);
344 
345 	append_string(res, strlen(res));
346 
347 	free(res);
348 }
349 
350 void zconf_starthelp(void)
351 {
352 	new_string();
353 	last_ts = first_ts = 0;
354 	BEGIN(HELP);
355 }
356 
357 static void zconf_endhelp(void)
358 {
359 	yylval.string = text;
360 	BEGIN(INITIAL);
361 }
362 
363 
364 /*
365  * Try to open specified file with following names:
366  * ./name
367  * $(srctree)/name
368  * The latter is used when srctree is separate from objtree
369  * when compiling the kernel.
370  * Return NULL if file is not found.
371  */
372 FILE *zconf_fopen(const char *name)
373 {
374 	char *env, fullname[PATH_MAX+1];
375 	FILE *f;
376 
377 	f = fopen(name, "r");
378 	if (!f && name != NULL && name[0] != '/') {
379 		env = getenv(SRCTREE);
380 		if (env) {
381 			snprintf(fullname, sizeof(fullname),
382 				 "%s/%s", env, name);
383 			f = fopen(fullname, "r");
384 		}
385 	}
386 	return f;
387 }
388 
389 void zconf_initscan(const char *name)
390 {
391 	yyin = zconf_fopen(name);
392 	if (!yyin) {
393 		fprintf(stderr, "can't find file %s\n", name);
394 		exit(1);
395 	}
396 
397 	current_buf = xmalloc(sizeof(*current_buf));
398 	memset(current_buf, 0, sizeof(*current_buf));
399 
400 	current_file = file_lookup(name);
401 	yylineno = 1;
402 }
403 
404 void zconf_nextfile(const char *name)
405 {
406 	struct file *iter;
407 	struct file *file = file_lookup(name);
408 	struct buffer *buf = xmalloc(sizeof(*buf));
409 	memset(buf, 0, sizeof(*buf));
410 
411 	current_buf->state = YY_CURRENT_BUFFER;
412 	yyin = zconf_fopen(file->name);
413 	if (!yyin) {
414 		fprintf(stderr, "%s:%d: can't open file \"%s\"\n",
415 			zconf_curname(), zconf_lineno(), file->name);
416 		exit(1);
417 	}
418 	yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
419 	buf->parent = current_buf;
420 	current_buf = buf;
421 
422 	current_file->lineno = yylineno;
423 	file->parent = current_file;
424 
425 	for (iter = current_file; iter; iter = iter->parent) {
426 		if (!strcmp(iter->name, file->name)) {
427 			fprintf(stderr,
428 				"Recursive inclusion detected.\n"
429 				"Inclusion path:\n"
430 				"  current file : %s\n", file->name);
431 			iter = file;
432 			do {
433 				iter = iter->parent;
434 				fprintf(stderr, "  included from: %s:%d\n",
435 					iter->name, iter->lineno - 1);
436 			} while (strcmp(iter->name, file->name));
437 			exit(1);
438 		}
439 	}
440 
441 	yylineno = 1;
442 	current_file = file;
443 }
444 
445 static void zconf_endfile(void)
446 {
447 	struct buffer *parent;
448 
449 	current_file = current_file->parent;
450 	if (current_file)
451 		yylineno = current_file->lineno;
452 
453 	parent = current_buf->parent;
454 	if (parent) {
455 		fclose(yyin);
456 		yy_delete_buffer(YY_CURRENT_BUFFER);
457 		yy_switch_to_buffer(parent->state);
458 	}
459 	free(current_buf);
460 	current_buf = parent;
461 }
462 
463 int zconf_lineno(void)
464 {
465 	return current_pos.lineno;
466 }
467 
468 const char *zconf_curname(void)
469 {
470 	return current_pos.file ? current_pos.file->name : "<none>";
471 }
472